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Heart Murmur

Topic Overview

What is a heart murmur?

A heart murmur is an extra sound that the
blood makes as it flows through the heart. Your doctor uses a stethoscope to
listen to your heartbeat. When you have a heart murmur, your doctor can hear an
extra whooshing or swishing noise along with your heartbeat.

It
can be scary to learn that you or your child has a heart murmur. But heart
murmurs are very common, especially in children, and are usually harmless.
These normal murmurs are called "innocent" heart murmurs. There is nothing
wrong with your heart when you have an innocent murmur. Up to half of all
children have innocent murmurs.footnote 1 They usually go away
as children grow.

Adults can have innocent murmurs too. Innocent murmurs are often found in adults over 50 years of age. Murmurs also
happen when your blood flows harder and faster than usual—during pregnancy, for
example, or a temporary illness, such as a fever.footnote 1

Sometimes, though, a heart murmur is a sign of a
heart problem. This is called an abnormal heart murmur.

What causes an abnormal heart murmur?

Abnormal
murmurs are signs of a heart problem. In children, abnormal heart murmurs are
usually caused by problems they are born with, such as a heart valve that
doesn't work right or a hole in the wall between two heart chambers.

In adults, abnormal murmurs are most often caused by damaged heart
valves. Heart valves operate like one-way gates, helping blood flow in one
direction between heart chambers as well as into and out of the heart. See a
picture of
blood flow through a normal heart.

When disease or an infection
damages a heart valve, it can cause scarring and can affect how well the valve
works. The valve may not be able to close properly, so blood can leak through.
Or the valve may become too narrow or stiff to let enough blood through. When a
damaged heart valve cannot close properly, the problem is called
regurgitation. When the valve can't let enough blood
through, the problem is called
stenosis.

Heart valves can be damaged by
heart disease or by infections like
rheumatic fever or
endocarditis. The normal wear and tear that comes with
aging can also cause some damage.

Some heart murmurs are caused by
a thicker than normal heart. When the heart muscle grows too large, it can get
in the way of normal blood flow and cause a murmur.

How is a heart murmur diagnosed?

Most heart
murmurs are found during regular doctor visits. During exams, doctors listen to
each part of the heartbeat, including any extra sounds, or murmurs, that may be
there.

If a doctor hears a murmur, he or she can often tell
whether it is innocent by how loud the noise is, what part of the heart it is
coming from, and what kind of sound it is. He or she will also look for signs
of a heart problem—for example, shortness of breath when the person is active,
lightheadedness, a fast or irregular heartbeat, or a buildup of fluid in the
legs or lungs. If your doctor thinks your murmur may be a sign of a problem,
you will have tests to check your heart. You may also be sent to a heart
specialist, called a
cardiologist, for more tests.

An
echocardiogram is a type of ultrasound test. It turns
sound waves into pictures that show how well your heart is working.

An
electrocardiogram, also called an EKG or ECG, checks
the electrical activity of your heart. It translates your heart's electrical
activity into line tracings on paper. The spikes and dips in the line tracings
are called waves.

A chest
X-ray shows the size and shape of your heart and the
position and shape of your large arteries.

Cardiac catheterization can check for defects in the heart. A thin tube is
inserted into an artery in your leg or arm. The tube, called a catheter, is
slowly pushed up to your heart. A small amount of dye is injected, and the
pictures show the heart chambers and valves as the dye moves through
them.

How is it treated?

If you have an innocent murmur,
you do not need treatment, because your heart is normal.

If you
have an abnormal murmur, treatment depends on the heart problem that is causing
the murmur and may include medicines or surgery. Not all abnormal murmurs need
to be treated. If you have an abnormal murmur and have no other symptoms, your
doctor may only monitor your condition with an echocardiogram.

If
you have symptoms, you may need to take medicine to lower your blood pressure
and reduce your heart's workload. You may need surgery to replace a valve or
repair a heart defect.

Can you prevent a heart murmur?

Most
heart murmurs are normal, and there is nothing you can
do to prevent them or cause them. They just happen.

Most abnormal
murmurs cannot be prevented, either. They are often caused by infections or by
problems that run in families.

What you can
do is take good care of your heart by living a heart-healthy lifestyle. This includes eating heart-healthy food, being active, staying at a healthy weight, and not smoking.

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